The present invention relates to a power line data transmission system. More particularly, the present invention relates to a data transmission system in which data may be transmitted over a line by modulating the power factor of the line, or in other words modulating or varying the phase angle between the voltage and the current on the line.
It has been known to transmit data over a power line by use of frequency displacement techniques. That is, it has been known to transmit data over a power line by modulating the power on a power cable with a high frequency carrier waveform containing the data.
The present invention may be used to transmit data between any two locations which are connected by a power line or cable. The present invention has found a significant use in transmitting data from the depths of oil well bore holes and other bore holes used in oil well exploration. However, the present invention may also be used in other applications to transmit data from one location to another.